doc: mention wal_receiver_status_interval as GUC affecting logical rep worker.

wal_receiver_timeout, wal_receiver_status_interval and
wal_retrieve_retry_interval configuration parameters affect the logical rep
worker, but previously only wal_receiver_status_interval was not mentioned
as such parameter in the doc.

Back-patch to v10 where logical rep was added.

Author: Masahiko Sawada
Discussion: https://www.postgresql.org/message-id/CAD21AoBUnuH_UsnKXyPCsCR7EAMamW0sSb6a7=WgiQRpnMAp5w@mail.gmail.com